Schistosoma mansoni: purification and characterization of a membrane-associated leucine aminopeptidase.
Membrane-associated leucine aminopeptidase (EC 3.4.11.1, LAP) has been purified to homogeneity from Schistosoma mansoni egg homogenates by a combination of ultracentrifugation, chromatofocusing, and molecular sieve chromatography. A 260-fold increase in specific activity was observed after purification. This is a metalloenzyme, containing carbohydrate moieties. Optimal enzyme activity was found at neutral pH. Enzyme activity was measured using L-leucine-7-amino-4-trifluoromethylcoumarin (L-Leu-AFC); in addition, schistosome egg LAP hydrolyzed a variety of other aminopeptidase substrates. Hydrolysis of L-Leu-AFC was inhibited by a number of aminopeptidase inhibitors, including 1,10-phenanthroline, bestatin, and amastatin.
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Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030.
Shawar
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Dresden
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D000818:Animals; D002498:Centrifugation; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007931:Leucyl Aminopeptidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D012550:Schistosoma mansoni / Q000201:enzymology*; D013379:Substrate Specificity
D007931:Leucyl Aminopeptidase